Model and Influence Factor Analysis of Three Principal Stresses in Directional Well

The principal stress is difficult to be solved in the directional well due to the influence of well trajectory/in-situ stress direction and other factors.The present principal stress models of wellbore are only useful at the well wall,not applicable for the location far away from wall.Through coordinate transformation method,the principal stress model is established and the factors affecting the principal stress are studied.The study results are significant for study of wellbore stability/hydraulic fracturing and other researches.